Development of a low cost culture medium for sakacin A production by L. sakei

MRS is currently the medium of choice for promoting sakacin A production by Lactobacillus sakei (180 a.u./ml): however, this medium is expensive and not applicable for large-scale production. In the present study, a one variable (factor) at a time (OVAT) approach was used to formulate an alternative culture medium.The subsequent full factorial design (25) investigated the influence of ingredients on bacteriocin production and interactions among the ingredients. A series of adaptation steps were used to develop an equation model that allowed for estimation of all first order variables and sakacin production. The formula of the alternative culture medium consisted as follows (g/l): bacto peptone (X1) 10, meat peptone (X2) 8, yeast autolysate (X4) 4, glucose 10, CaCO3 30, inoculum 5% (v/v) and use of deionised water. The cost of the alternative medium was approximately half that of MRS and sakacin A production was increased from 180 to 480 a.u./ml.